动脉粥样硬化小鼠肝脏脂质代谢相关的PPAR-γ/LXR-α/ABCG1通路及炎症因子的变化和化瘀祛痰方在其中的作用

Changes of liver lipid metabolism-related PPAR-γ/LXR-α/ABCG1 pathways and inflammatory factors in atherosclerotic mice and role of Huayu-Qutan recipe

目的:观察动脉粥样硬化(AS)小鼠肝脏脂质代谢相关的过氧化物酶体增殖物激活受体γ(PPAR-γ)/肝X受体α(LXR-α)/ATP结合盒转运体G1(ABCG1)通路和炎症因子的变化,以及化瘀祛痰方在其中的作用,探讨化瘀祛痰方对肝脏脂质代谢及炎症反应的影响及作用机制。方法:将24只ApoE-/-小鼠随机分为模型组、化瘀祛痰方组和辛伐他汀组,8只C57BL/6J小鼠作为正常对照组。除正常对照组给予基础饲料外,其余各组给予高脂饲料。造模12周后,灌胃给药,化瘀祛痰方组与辛伐他汀组给予相应药物,正常对照组与模型组给予等体积的生理盐水。8周后用全自动生物化学分析仪检测血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的含量;HE和油红O染色观察肝脏组织病理及脂质的变化情况;ELISA法检测肝脏游离脂肪酸(FFA)、TG、肿瘤坏死因子α(TNF-α)、Toll样受体4(TLR4)和白细胞介素1β(IL-1β)的含量;Western blot法检测PPAR-γ、LXR-α和ABCG1的蛋白表达。结果:与正常对照组比较,模型组小鼠血清TC、TG和LDL-C含量显著上升(P<0.01),HDL-C含量显著降低(P<0.01);肝脏脂肪变性,细胞变大,脂质沉积明显,FFA和TG含量显著上升(P<0.01),炎症因子TLR4、TNF-α和IL-1β的含量显著增加(P<0.01),脂质代谢通路相关因子PPAR-γ、LXR-α和ABCG1的蛋白表达显著降低(P<0.05或P<0.01)。与模型组比较,服用辛伐他汀和化瘀祛痰方可使小鼠血清TC、TG和LDL-C含量显著下降(P<0.05或P<0.01),HDL-C含量显著上升(P<0.01);肝脏脂肪变性减轻,脂质沉积不同程度降低,FFA和TG含量显著下降(P<0.05或P<0.01),TLR4、TNF-α和IL-1β含量显著降低(P<0.01),PPAR-γ、LXR-α和ABCG1的蛋白表达显著增高(P<0.05或P<0.01)。结论:化瘀祛痰方可能通过调控肝脏PPAR-γ/LXR-α/ABCG1通路及减弱肝脏TRL4介导的炎症反应来达到抗AS的作用。

AIM:To observe the changes of liver lipid metabolism-related peroxisome proliferator-activated receptor-γ(PPAR-γ)/liver X receptor-α(LXR-α)/ATP-binding cassette transporter G1(ABCG1)signaling pathways and inflammatory factors in mice with atherosclerosis(AS),and to investigate the effects of Huayu-Qutan recipe(HYQT)on hepatic lipid metabolism and inflammatory response and the mechanisms.METHODS:ApoE-/-mice(n=24)were randomly divided into model group,HYQT group and simvastatin group,and C57BL/6J mice(n=8)were used as control group.Except for the control group,the mice in other groups were given high-fat diet.After 12 weeks of modeling,the mice in HYQT and simvastatin groups were intragastrically given the corresponding drugs,and the mice in control and model groups were given the same volume of normal saline.After 8 weeks,the serum levels of triglyceride(TG),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)were measured by an automatic biochemical analyzer.HE and oil red O staining was used to observe liver histopathological and lipid changes.The hepatic levels of free fatty acid(FFA),TG,tumor necrosis factor-α(TNF-α),Toll-like receptor 4(TLR4)and interleukin-1β(IL-1β)were detected by ELISA.The protein expression of PPAR-γ,LXR-αand ABCG1 was determined by Western blot.RESULTS:Compared with control group,the serum levels of TC,TG and LDL-C in model group were significantly increased(P<0.01),and the HDL-C content was significantly decreased(P<0.01).Liver steatosis,cell size augmentation and lipid deposition were obvious,and liver FFA and TG levels were significantly increased(P<0.01).The liver levels of TLR4,TNF-αand IL-1βwere significantly increased(P<0.01),while the protein expression of PPAR-γ,LXR-αand ABCG1 was significantly decreased(P<0.05 or P<0.01).Compared with model group,the serum levels of TC,TG and LDL-C in simvastatin group and HYQT group were significantly decreased(P<0.05 or P<0.01),and the HDL-C content was significantly increased(P<0.01).Liver steatosis was weakened,and liver lipid deposition and FFA and TG levels were significantly decreased(P<0.05 or P<0.01).The liver levels of TLR4,TNF-αand IL-1βwere significantly decreased(P<0.01),while the protein expression of PPAR-γ,LXR-αand ABCG1 was significantly increased(P<0.05 or P<0.01).CONCLUSION:Huayu-Qutan recipe may exert anti-AS effect by regulating liver PPAR-γ/LXR-α/ABCG1 pathways and attenuating liver TRL4-mediated inflammatory responses.